Characterization of the excess carrier lifetime of as-grown and electron irradiated epitaxial p-type 4H-SiC layers by the microwave photoconductivity decay method

Matsushita, Yoshinori*; Kato, Masashi*; Ichimura, Masaya*; Hatayama, Tomoaki*; Oshima, Takeshi

Silicon carbide (SiC) is a promising material for radiation hardness devices. In this study, we evaluated excess carrier decay curves in both as-grown and electron-irradiated p-type 4H-SiC layers by the microwave photoconductivity decay (-PCD) method. The samples used in this study were an Al-doped p-type epitaxial layer grown on a Si-face B doped bulk p-type 4H-SiC. The samples were irradiated with electrons at an energy of 160 keV and at a doses of 110 cm (ele-16) and 110 cm (ele-17). As a results of -PCD measurements, the lifetimes of free carriers for as-grown, ele-16 and ele-17 were estimated to be 0.14 s, 0.07 s and 0.04 s, respectively. This result indicates that defects acting as recombination centers were introduced by the electron irradiation.